Abstract: Substrates for .beta.-lactamase of the general formula I ##STR1## in which one of X and Y is a fluorescent donor moiety and the other is a quencher (which may or may not re-emit); R' is selected from the group consisting of H, lower (i.e., alkyl of 1 to about 5 carbon atoms) and (CH.sub.2).sub.n OH, in which n is 0 or an integer from 1 to 5; R" is selected from the group consisting of H, physiologically acceptable metal and ammonium cations, --CHR.sup.2 OCO(CH.sub.2).sub.n CH.sub.3, --CHR.sup.2 OCOC(CH.sub.3).sub.3, acylthiomethyl, acyloxy-alpha-benzyl, delta-butyrolactonyl, methoxycarbonyloxymethyl, phenyl, methylsulphinylmethyl, beta-morpholinoethyl, dialkylaminoethyl, acyloxyalkyl, dialkylaminocarbonyloxymethyl and aliphatic, in which R.sup.2 is selected from the group consisting of H and lower alkyl; A is selected from the group consisting of S, O, SO, SO.sub.2 and CH.sub.2 ; and Z' and Z" are linkers for the fluorescent donor and quencher moieties. Methods of assaying .beta.

Abstract: Membrane-permeant phosphoinositides, including phosphatidylinositol phosphate esters, are described. A membrane-permeant phosphoinositide includes groups that neutralize the charges of the phosphate moieties of the phosphoinositide. A cell can be treated with the membrane-permeant phosphoinositide, which is then absorbed into the cell. The neutralizing groups can be removed intracellularly to afford the charged phosphoinositide.

Abstract: The present invention features biarsenical molecules and target sequences that specifically react with the biarsenical molecules. Bonding partners that include target sequences, vectors that include nucleic acid sequences that encode the target sequences and host cells that include the target sequences are also featured in the invention.

Abstract: This invention provides assays for protein kinase activity using fluorescent proteins engineered to include sequences that can be phosphorylated by protein kinases. The proteins exhibit different fluorescent properties in the non-phosphorylated and phosphorylated states.

Abstract: This invention provides assays for protein kinase activity using fluorescent proteins engineered to include sequences that can be phosphorylated by protein kinases. The proteins exhibit different fluorescent properties in the non-phosphorylated and phosphorylated states.

Abstract: The invention provides for multi-well plates with greater than 864 wells that comprise a layer of cycloolefin having low fluorescence and high transmittance. These multi-well plates are particularly well suited for fluorescence measurements.

Abstract: Caged acyloxyalkyl esters of phosphate-containing inositol phosphates which are capable of permeating cell membranes. The second messengers are protected (caged) at the 6-hydroxyl, with a photolabile group. Once inside the cell, the ester derivatives undergo enzymatic conversion to remove the acyloxyalkyl ester groups. The resulting caged compound remains biologically inactive until exposed to ultraviolet (UV) light. Upon UV light exposure, the active form of the second messenger is released within the cell.

Abstract: Acyloxyalkyl esters of phosphate-containing second messengers which are capable of permeating cell membranes. Once inside the cell, the ester derivatives undergo enzymatic conversion to the biologically active form of the second messenger. The acyloxyalkyl esters have the formula: ##STR1## wherein A.sub.1 to A.sub.6 is H, OH, F or ##STR2## wherein R is an alkyl group having from 2 to 6 carbon atoms and R' is H or CH.sub.3 or R is CH.sub.3 and R' is CH.sub.3 and wherein at least one of A.sub.1 to A.sub.6 is a phosphoester having the formula set forth above.

Abstract: Modifications in the sequence of Aequorea wild-type GFP provide products having markedly different excitation and emission spectra from corresponding products from wild-type GFP. In one class of modifications, the product derived from the modified GFP exhibits an alteration in the ratio of two main excitation peaks observed with the product derived from wild-type GFP. In another class, the product derived from the modified GFP fluoresces at a shorter wavelength than the corresponding product from wild-type GFP. In yet another class of modifications, the product derived from the modified GFP exhibits only a single excitation peak and enhanced emission relative to the product derived from wild-type GFP.

Abstract: Fluorogenic substrates of the general formula I ##STR1## in which one of X and Y is a fluorescent donor moiety and the other is a quencher (which may or may not re-emit); R' is selected from the group consisting of H, lower (i.e., alkyl of 1 to about 5 carbon atoms) and (CH.sub.2 OH).sub.n OH, in which n is 0 or an integer from 1 to 5; R" is selected from the group consisting of H, physiologically acceptable metal and ammonium cations, --CHR.sup.2 OCO(CH.sub.2).sub.n CH.sub.3, --CHR.sup.2 OCOC(CH.sub.3).sub.3, acylthiomethyl, acyloxy-alpha-benzyl, delta-butyrolactonyl, methoxycarbonyloxymethyl, phenyl, methylsulphinylmethyl, beta-morpholinoethyl, dialkylaminoethyl, acyloxyalkyl, dialkylaminocarbonyloxymethyl and aliphatic, in which R.sup.2 is selected from the group consisting of H and lower alkyl; A is selected from the group consisting of S, O, SO, SO.sub.2 and CH.sub.2 ; and Z' and Z" are linkers for the fluorescent donor and quencher moieties. The substrates are useful in conjunction with .beta.

Abstract: Acyloxyalkyl esters of phosphate-containing second messengers which are capable of permeating cell membranes. Once inside the cell, the ester derivatives undergo enzymatic conversion to the biologically active form of the second messenger. Acyloxyalkyl esters of second messengers, such as cAMP, cGMP, inositol triphosphate and inositol tetraphosphate are disclosed.

Abstract: Compositions and methods for use in generating fast ratiometric voltage-sensitive fluorescence changes in single or multiple cells systems. A first reagent is a membrane-bound hydrophobic fluorescent anion which rapidly redistributes from one face of the plasma membrane to the other in response to the transmembrane potential, as described by the Nernst equation. A voltage-sensitive fluorescent readout is created by labeling the intracellular or extracellular surface of the cell with a second reagent comprising a fluorophore which can undergo energy transfer with the first reagent or a quencher for the first reagent. Quenching or FRET between the two reagents is disrupted when the membrane potential is depolarized, because the anionic first reagent is pulled to the intracellular surface of the plasma membrane far from the asymmetrically bound second reagent. In preferred embodiments of the invention, the first and second reagents are bound together by a suitable linker group.

Abstract: Modifications in the sequence of Aequorea wild-type GFP provide products having markedly different excitation and emission spectra from corresponding products from wild-type GFP. In one class of modifications, the product derived from the modified GFP exhibits an alteration in the ratio of two main excitation peaks observed with the product derived from wild-type GFP. In another class, the product derived from the modified GFP fluoresces at a shorter wavelength than the corresponding product from wild-type GFP. In yet another class of modifications, the product derived from the modified GFP exhibits only a single excitation peak and enhanced emission relative to the product derived from wild-type GFP.

Abstract: The present invention relates to a group of organic chelators whose affinity for calcium ion in solution is decreased by electromagnetic radiation. Specifically, the chelators are related to fura-2 and utilize the addition of an azide group to the 3-position of the benzofuron ring of a fura-2 type structure. Photolysis of the azide group causes the calcium ion affinity to decrease 100 to 1000 fold. These chelators when incorporated into rat fibroblasts either by microinjection or by incubation as the membrane-permeable, enzymatically-labile esters and flash-photolyzed cause large increases in intracellular free calcium ion. These chelators are used to generate controlled fast elevation of intracellular free calcium ion concentration to mimic or modulate a number of important cellular responses, especially in nerve or muscle.

Abstract: The present invention relates to a group of organic chelators whose affinity for calcium ion in solution is decreased by electromagnetic radiation. Specifically, the chelators are related to fura-2 and utilize the addition of an azide group to the 3-position of the benzofuran ring of a fura-2 type structure. Photolysis of the azide group causes the calcium ion affinity to decrease 100 to 1000 fold. These chelators when incorporated into rat fibroblasts either by microinjection or by incubation as the membrane-permeable, enzymatically-labile esters and flash-photolyzed cause large increases in intracellular free calcium ion. These chelators are used to generate controlled fast elevation of intracellular free calcium ion concentration to mimic or modulate a number of important cellular responses, especially in nerve or muscle.

Abstract: The invention provides labeled proteins suitable for determining the presence of cAMP, other second messengers and organic molecules. The proteins are separately labeled with fluorochromes which, when in close spatial proximity, preferably, less than about 6 nm, interact through the transfer of energy from one fluorochrome to the other.A composition of matter, (S.sub.1.A).sub.n1 (S.sub.2.D).sub.n2 is provided wherein S.sub.1 and S.sub.2 are two proteins which are associated in one state and substantially disassociated in another, the equilibrium between which is controlled by the free concentration of an analyte, and A and D are fluorochromes, the emission wavelength of fluorochrome D overlapping the excitation wavelength of fluorochrome A and the distance between A and D being in sufficiently close proximity to allow the radiationless transfer of energy between the fluorochromes.

Abstract: Chemical derivatives of nitric oxide are provided which are stable indefinitely in oxygen-containing solutions until photolysis, whereupon they release NO. These compounds have the general formulaA--N.sup.+ (O.sup.-)=N--O--B (I)wherein A is typically a nitrogen- or oxygen-containing substituent and B is a group lablie to photolysis. The compounds are stable and inert in oxygenated aqueous solutions, but release NO upon illumination. Given the ease with which the intensity, timing and location of illumination may be controlled, these compounds are particularly useful in investigating the biological effects of NO with much higher spatial or temporal resolution than heretofore possible.

Abstract: A scanning confocal microscopes scans a sample with an incident beam of ultraviolet radiation, in a raster scan pattern, causing the sample to fluoresce and emit visible radiation, a portion of which retraces a 5 portion of the path optical of incident beam, to a dichroic mirror that separates it from the incident beam for detection by a photomultiplier tube. A clock signal for clocking the output of the photomultiplier tube is provided by a reference beam system that directs a reference beam onto the same scanning mirror as is the incident beam, at a coincident location on that mirror, and from there through a Ronchi grating having a uniform series of alternating transparent and opaque regions. The resulting pulsed reference beam is detected by a second photomultiplier tube, to produce a clock signal that is an accurate representation of the instantaneous scan rate of the reference beam and, thereby, the scanning incident beam.

Abstract: A scanning confocal microscope scans a sample with an incident beam of radiation, in a raster scan pattern, causing the sample to fluoresce and emit visible radiation in at least two wavelengths. A portion of the fluorescent light retraces a portion of the path optical of incident beam, to a dichroic mirror that separates it from the incident beam for detection by a pair of photomultiplier tubes. A data processor accumulates digital data from the photomultiplier tubes to form a succession of image data frames of the sample being scanned, in the two wavelengths. Image data for a selected number of frames in each wavelength is averaged and then recorded on a single track of a recording system, in an alternating fashion with averaged data for the other wavelength. In addition, a ratio of the averaged data for the two wavelengths is delivered to a video display.

Abstract: The present invention relates to a group of organic chelators whose affinity for calcium ion in solution is increased by electromagnetic radiation. Specifically, the chelators are related to BAPTA and utilize the addition of an electron-withdrawing group (e.g., diazocarbonyl) to a ring of BAPTA, para to the amino group. Photochemical rearrangement of the diazoacetyl group converts the group to the electron-donating carboxymethyl group, causing the calcium ion efficiency to increase 25 to 50 fold. These chelators when incorporated into rat fibroblasts either by microinjection or by incubation as the membrane-permeable, enzymatically-labile tetraacetoxymethyl ester and flash-photolyzed cause a drop in intracellular free calcine ion to or below resting valves of about 10.sup.-7 M. These chelators are used to generate controlled fast removal of intracellular free calcium ion to mimic or modulate a number of important cellular responses, especially in nerve or muscle.